Abstract

Context Fistula formation between the pancreas and adjacent organs has been reported in up to 6.6% of Intraductal papillary mucinous neoplasm cases of the pancreas. Pancreaticobiliary fistulas connect the intrapancreatic portion of the common bile duct and the main pancreatic duct. Case report Herein we report a case of an eighty-year-old man presented with a main pancreatic duct - intraductal papillary mucinous neoplasm complicated by PB fistula and obstructive cholangitis caused by the impaction of thick mucus protruding from the pancreas into the bile duct. In the present case, the main difficulty was the control of sepsis and jaundice related to the PB fistula. Endoscopic retrograde cholangiopancreatography was undertaken to confirm pancreaticobiliary fistulas and perform common bile duct drainage. Thick mucus flowing from the papilla revealed “pig-nose” appearance. Three endoscopic procedures were required because of failure to obtain effective common bile duct drainage due to stent migration and obstruction. Eventually a large covered biliary metallic stent was positioned to treat recurrent obstructive cholangitis. Combined with prolonged antibiotherapy these manoeuvres allowed biliary sepsis control, but jaundice persisted. A surgical approach was then decided to treat both persistent obstructive jaundice and the intraductal papillary mucinous neoplasm. Conclusion Pancreaticobiliary fistulas fistula presenting as jaundice and /or cholangitis is a rare condition and is associated with malignancy in half of the patients. Biliary stenting remains the first line treatment but fails to control symptoms in half of the cases. Under such circumstances resective surgery is a radical treatment that resolves both the symptoms and the cause of PB fistula and should not be delayed.

Keywords

Jaundice, Obstructive; Pancreatic Ducts; Pancreatic Fistula

Abbreviations

INTRODUCTION

Intraductal papillary mucinous neoplasms (IPMN) of
the pancreas are increasingly recognized and currently
account for 20% of resected pancreatic neoplasms.
Symptomatic IPMN commonly present with recurrent
pancreatitis, chronic abdominal pain, or jaundice. Fistula
formation between the pancreas and adjacent organs
has been reported in up to 6.6% of IPMN cases, with the
duodenum (67%), the stomach (44%) and the common
bile duct (CBD) (33%) being the most frequently affected
sites; up to 39% of the patients show multiple fistula
formation [1, 2, 3]. Pancreaticobiliary fistulas (PB) connect
the intrapancreatic portion of the CBD and the main
pancreatic duct (MPD). Reports of PB associated with IPMN and manifesting as obstructive jaundice are scarce
in the literature [1, 4, 5, 6, 7, 8]. Herein we report a case
of a MPD-IPMN complicated by PB fistula and obstructive
cholangitis caused by the impaction of thick mucus
protruding from the pancreas into the bile duct. A written
informed consent was obtained from the patient.

CASE REPORT

An eighty-year-old man presented with right upper
quadrant pain, jaundice, fever and weight loss. He
had a 15-years history of type-2 diabetes mellitus. On
admission, physical examination revealed obstructive
cholangitis. The initial biological investigations revealed
deranged liver function tests consistent with cholestasis
and increased inflammatory tests (white blood count, C
reactive protein). Computed tomography of the upper
abdomen showed dilatation of the intrahepatic bile
duct, CBD, and MPD without evidence of pancreatic head
mass. Magnetic resonance imaging (MRI) also showed
dilatation of the CBD and MPD, and multiple cystic masses
located in all pancreatic segments; cholelithiasis was
not demonstrated in the gallbladder and the common
bile duct. Both radiological exams showed a large PB
fistula connecting the intrapancreatic portion of the CBD
and the MPD (Figures 1a, b). Endoscopic retrograde cholangiopancreatography (ERCP) was undertaken to
confirm PB fistula and perform CBD drainage. Thick mucus
flowing from the papilla revealed “pig-nose” appearance,
and selective cholangiography showed a short distal
CBD stricture with proximal filling defects and outlined
amorphous material obstructing the lower part of the
CBD. Sphincterotomy was performed and a plastic biliary
stent was inserted to treat the bile duct obstruction. Two
additional endoscopic procedures were required because
of failure to obtain effective CBD drainage due to stent
migration and obstruction. Eventually a large covered
biliary metallic stent was positioned to treat recurrent bile
duct obstruction (Figure 1c) and to exclude the PB fistula (Figure 1d); combined with prolonged antibiotherapy
these manoeuvres allowed biliary sepsis control, but
jaundice still persisted. A surgical approach was then
decided to treat both persistent obstructive jaundice
and the IPMN; intraoperative exploration revealed hardtexture
pancreatic parenchyma, and a large cystic lesion
in the head of the pancreas (Figure 2a). Due to the diffuse
involvement of the pancreas by IPMN total pancreatectomy
was undertaken (Figure 2b, c). Transection of the bile
duct revealed thick mucin within the lumen of the metallic
duodenal stent. Frozen-section examination of the biliary resection margin revealed no evidence of malignant
involvement. Macroscopic examination of the specimen
revealed thick mucus protruding from the pancreas via a
large PB fistula with a diameter >15 mm which connected
the intrapancreatic portion of the CBD and the MPD (Figure 2d). Pathological examination of the operative
specimen revealed intestinal-type IPMN and high-grade
dysplasia with focal in–situ invasive carcinoma (pTis N0
M0). Malignancy was not recorded at the site of the PB
fistula. The postoperative course was uneventful, and the
patient was discharged from hospital on POD 19.

Figure 1: Preoperative assessment.

Figure 2: Operative and histopathological findings.

DISCUSSION

In the present case, the main difficulty was the control
of sepsis and jaundice related to the PB fistula. Several
endoscopic procedures were necessary to treat obstructive
cholangitis but did not allow complete regression of
jaundice due to stent migration and obstruction by thick
mucus. Eventually these complications were successfully
managed by total pancreatectomy.

In the literature, fistula formation was reported in
6.6% of the IPMN patients, of whom 94% had intestinaltype
IPMN [2]. Most of the PB fistula associated with IPMN has been identified by either ERCP, endoscopic
ultrasonography or during surgery [2, 4]; our experience
suggests that CT and MRI are also reliable in identifying
large PB fistulas [3]. However it has been reported that, CT,
MRI and ERCP are less performant for the diagnosis of small
size PB fistulas [4, 6], due to thick mucus obstructing the
CBD. In patients with IPMN, the resulting ERCP “pig-nose”
appearance of the duodenal papilla, (dilation of both bile
and pancreatic ducts due to thick mucus extrusion), may
be suggestive of PB fistula [6]. Intraductal ultrasonography
(IDUS) has proven the best diagnostic tool for IPMN relate
PB fistulas in two specific settings: (1) after ERCP failure
to detect the fistula; under these circumstances IDUS can
be performed following ERCP; (2) in the presence of the
“pig-nose” anomaly, because IDUS visualizes the CBD wall
and its surrounding structures with higher resolution than
CT and MRI [6].

PB fistula was not associated with malignant invasion in
approximately half of the published cases; in the absence of
malignancy PB fistula is probably secondary to mechanical
compression by the cyst or/and mucin impaction within
the lumen of the bile duct [1, 2, 4, 6]. Yamaguchi et al. [9] reported that mean survival times in patients with PB fistula associated with IPMN who underwent surgical
resection versus those who did not undergo surgical
resection were 47.9 and 10.4 months, respectively.

The incidence of obstructive jaundice due to the
mucinous material of PB fistula associated with IPMN
was 97.1% [9]. When PB fistula associated with IPMN is
revealed by obstructive jaundice, short term prognosis
is conditioned by cholangitis. This situation is very
rare and, in our knowledge, only 8 cases were reported
in the literature [1, 4, 5, 6, 7, 8]. Management of this
condition included ERCP drainage (n=6), percutaneous
transhepatic drainage (n=1) and pancreatic resection
(n=1) [4, 5, 6, 7, 8]. Similarly to our case, failure to obtain
an effective biliary drainage required pancreatic resection
(duodenopancreatectomy, n=5), and 2 patients died as a
result of sudden worsening of cholangitis before surgery
[4, 5, 6, 7, 8].

Relieving obstructive jaundice due to IPMN related is a
challenging task. Of the 8 cases reported (including ours)
biliary stenting was effective for the control of cholangitis
in 6 patients and the control of jaundice in 3 patients [4, 5, 6, 7, 8]. In 4 of the 7 patients who underwent preoperative
biliary drainage, several procedures were required to allow sepsis control due to the small size of endoscopic
biliary drain tube or stent migration, and a fully covered
biliary metallic stent was inserted for fistula coverage and
biliary drainage in 4 patients [4, 5, 6, 7, 8]. Reported cases
and our experience, showed that several biliary drainage
procedures are probably necessary to treat biliary
obstruction associated with PB fistula, and that large
metallic stent is required to allowed biliary sepsis control
more than plastic stent [4, 5, 6, 7, 8]. Nevertheless, biliary
stenting eventually failed in half of the patients because of
the viscosity of the mucus in the bile; surgery is the most
reliable treatment option under such circumstances [10].

CONCLUSION

In conclusion PB fistula presenting as jaundice and /
or cholangitis is a rare condition and is associated with
malignancy in half of the patients. Biliary stenting remains
the first line treatment but fails to control symptoms in half
of the cases. Under such circumstances resective surgery is
a radical treatment that resolves both the symptoms and
the cause of PB fistula and should not be delayed.

Conflict of Interest

There are no conflicts of interest or financial disclosure
to declare.